ECR Minerals plc (LSE:ECR), the precious metals exploration and development company, is pleased to provide an update in respect of the Company’s exploration programme at the Creswick gold project (the “Project”) in Victoria, Australia.
- The Company has completed 1,687 metres of reverse circulation drilling in 17 holes at the Creswick gold project targeting multiple quartz vein orientations within the Dimocks Main Shale (“DMS”);
- Drilling identified more extensive quartz than anticipated, in a zone exceeding 60m in width (more than twice the 25m width expected) with quartz identified in over one third of the 1,687 metres drilled;
- The majority of drill results have now been received and are being reviewed by the Company’s technical team. Of the 17 holes drilled the Company has identified gold mineralisation in all holes so far with grades in 9 holes ranging from 0.6 g/t gold to 44.63 g/t gold (1.44 oz per tonne);
- Technical review of the drill programme and assay results has confirmed elements of the complex geology at Creswick and confirmed that the gold mineralisation is ‘nuggetty’ in nature;
- Nuggetty gold distribution can lead to understated assays, as the larger the nuggets the less the chance they will be captured in the drilled metre. Compounding the problem is only a small portion of each reverse circulation sample bag is actually tested. Conversely results can be overstated if the nugget happens to be captured in the small sample;
- ECR has therefore commenced a process of gravity concentration tests from whole of bag samples from the reverse circulation drilling and will release results as the more representative whole of sample bag analyses are conducted;
- From a trial sample bag tested from hole CSR011 a nugget has been found in the previously untested portion of the sample and overall the sample has demonstrated gold of 11.8 g/t from whole-of-bag gravity concentration, some 528% greater than the 1.88 g/t assay result;
- Until further extensive whole-of-bag tests have been completed the results of the assays from the drilling program may be unreliable as indicators of true grade at this stage;
- The work undertaken indicates that we believe there is potential for a very substantial gold deposit within the DMS as highlighted previously by the Company’s technical team and ECR is now accelerating the highly important gravity concentration tests as outlined;
- A fuller explanation of the nugget effect and its implications is provided below and further updates will be announced to market as soon as practicable.
Craig Brown, Chief Executive Officer commented: “The work we are undertaking at Creswick is highly exciting given the transformational potential this large footprint gold system offers.
The question we have to answer is how much gold does the DMS hold that would be amenable to a bulk tonnage gold mining operation. We are closing in on the answer and the directors believe that the outcome has the potential to be Company transformational and is therefore deserving of our close attention.
We eagerly await the findings from the whole of bag gravity concentration work and will report back to the market as significant developments occur.”
Within the Company’s announcement dated 25 September 2018 it was confirmed that exploration mapping undertaken by the Company at the Project had identified a large gold system in the Dimocks Main Shale (“DMS”) gold targets. The announcement can be viewed through the following link:
The DMS sits between two large gold producing areas in Victoria, Australia where it is estimated that, historically, 15 million ounces of gold has been produced. It was the proposition of the Company’s technical team that they had identified the hard rock source for a significant portion of the aforementioned 15 million ounces of gold,. although further work was required to validate this proposition.
A visual representation of the DMS and the Company’s mapping, which demonstrates the potential link from the alluvial source with the DMS, is provided through following links to the ECR Minerals website:
Reverse Circulation Programme:
On 28 January 2019 the Company announced the commencement of a reverse circulation drilling programme targeting multiple quartz vein orientations identified within the DMS.
The majority of drill results have now been received and are being reviewed by the Company’s technical team. Of the 17 holes drilled the Company has identified gold mineralisation in 9 holes so far with grades ranging from 0.6 g/t to 44.63 g/t (1.44 ounces per tonne).
Further information in respect of the drill programme and the complete assay results will be provided in due course when all results have been received and analysed by the Company’s technical team; and alongside other important exploration and investigative work as outlined below.
Gold Nugget Effect – Creswick Project
The gold mineralisation at the Project is reef gold, with alluvial free gold which has eroded from the reef into the surrounding gullies. This means that in our earlier work we identified that a proportion of the in-situ gold has a nuggetty distribution across the DMS.
The drill testing programme was designed to examine this proposition, and the indications thus far demonstrate that the proposition of an extreme nuggetty distribution rather than major, minor or none. This is not unusual in these gold systems and Bendigo and Wattle Gully (Castlemaine) have an extreme nugget effect, whereas other deposits in Victoria and elsewhere are less (Dominy et al. 2004).
The State of Victoria in Australia is renowned for large gold nuggets and in the list of nuggets published by the Geological Survey of Victoria (Dunn, 1912) it is reported there was a 112 oz nugget found in a mine understood to be adjacent to one of the Company’s drill locations at the Project (hole CSR014). In addition, it is reported several nuggets over 100 oz were found in the vicinity of the Company’s drill targets and nuggets up to 625 oz further south in alluvial gullies downstream from the DMS.
The reverse circulation drilling programme has identified gold mineralisation, and the higher grade identified by the whole-of-bag test, indicates the potential for significant grades. With nuggetty gold however, the traditional assay testing can materially understate or overstate the gold in the samples.
The reason for this potential understatement is that nuggetty gold may be missed when samples from the reverse circulation drill holes are sent for assay. This arises from having the gold concentrated in a few large particles reducing the chances of a gold particle being captured in a small sample.
In respect of the Creswick programme typically 1 metre of reverse circulation drilling collected a 30kg sample. From each 30kg sample bag typically 2kg was sent to the assay laboratory, pulverised and subjected to the Leachwell method of analysis.
This means that from each 1 metre sample bag 93% of the contents were not initially tested and any nuggets within that untested portion of the sample would not be represented in the assay data.
The Company could have tested whole-of-bag samples from the beginning of the process, but that would have been a costly exercise prior to drilling completion, analysis of samples and initial assay testing.
With the benefit of the initial field work and sample analysis, together with guidance from the incoming assay results, the Company’s technical team has concluded that testing of the whole contents of each sample bag is required to fully assess the gold content.
After consideration of various methods the Company determined that the entire 30 kg sample in each bag should be subject to a gravity concentration test.
A trial bag has been tested and a 6.4mm 0.27g nugget was found in material from a 22.9kg sample bag. This which equates to 11.8 g/t from hole CSR011. The actual assay result for the 2kg sample from CSR011 was only 1.88 g/t. This reliably demonstrates that for the first bag fully tested by gravity concentration the initial assay test had understated the gold content by 84.2%.
As a result, the Company is now processing further whole-of-bag samples through the gravity concentration testing process.
Whilst there can be no certainty that additional bags tested will contain higher quantities of gold, it is unlikely that the testing will not find a degree of repetition of this type of result recognising what is now known about the DMS geology.
Should however the Company find in the testing process that considerable gold is identified, in nugget form, this may indicate a substantial in-situ gold deposit which may be amenable to a bulk tonnage mining operation.
Further testing is ongoing at present and the Company will be releasing regular updates with regard to this very important work.
Dominy, S. C., Cuffley, B. W., McCarthy, P. L., Thomas, O. K. & Hill, R. L., 2004. The challenges of evaluating and exploiting gold-quartz reefs in the Central Victorian Goldfield, Australia. The AusIMM New Leaders’ Conference, Ballarat. pp121-141
Dunn, E. J. 1912. List of nuggets found in Victoria. Geological Survey of Victoria. Memoir 12.
Table 1. Tabulated intersections (> 0.5 g/t gold).
|HoleID||Interval (m)||From (m)||To (m)||Grade (g/t gold)|
Table 2. Hole details.
|Hole ID||Easting (m)||Northing (m)||Elevation (m)||Zone||Hole depth (m)||Delination||Azimuth|
COMPETENT PERSON STATEMENT
The information in this announcement that relates to Exploration Results is based on information compiled by Dr Rodney Boucher of Linex Pty Ltd. Linex Pty Ltd provides geological services to Mercator Gold Australia Pty Ltd, including the services of Dr Boucher, who has a PhD in geology, is a Member and RPGeo of the Australian Institute of Geoscientists and is a Member of the Australasian Institute of Mining and Metallurgy. Dr Boucher has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Dr Boucher consents to the inclusion in the announcement of the material based on his information in the form and context in which it appears.
MARKET ABUSE REGULATIONS (EU) No. 596/2014
The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 (MAR). Upon the publication of this announcement via Regulatory Information Service (RIS), this inside information is now considered to be in the public domain.
FOR FURTHER INFORMATION, PLEASE CONTACT:
|ECR Minerals plc||Tel: +44 (0)20 7929 1010|
|David Tang, Non-Executive Chairman|
|Craig Brown, Director & CEO|
|WH Ireland Ltd||Tel: +44 (0)161 832 2174|
|Katy Mitchell/James Sinclair-Ford|
|SI Capital Ltd||Tel: +44 (0)1483 413500|
ABOUT ECR MINERALS PLC
ECR is a mineral exploration and development company. ECR’s wholly owned Australian subsidiary Mercator Gold Australia Pty Limited has 100% ownership of the Avoca, Bailieston, Creswick, Moormbool and Timor gold exploration licences in central Victoria, Australia and the Windidda Gold Project in the Yilgarn Region, Western Australia.
ECR has earned a 25% interest in the Danglay epithermal gold project, an advanced exploration project located in a prolific gold and copper mining district in the north of the Philippines. An NI43-101 technical report was completed in respect of the Danglay project in December 2015 and is available for download from ECR’s website.
ECR’s wholly owned Argentine subsidiary Ochre Mining has 100% ownership of the SLM gold project in La Rioja, Argentina. Exploration at SLM has focused on identifying small tonnage mesothermal gold deposits which may be suitable for relatively near-term production.